Pitting Corrosion of a Low Carbon Steel in Corrosive Environments: Experiments and Models

2015 ◽  
Vol 1132 ◽  
pp. 349-365 ◽  
Author(s):  
S.K. Kolawole ◽  
F.O. Kolawole ◽  
O.P. Enegela ◽  
O.O. Adewoye ◽  
A.B.O. Soboyejo ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Pitting Corrosion ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Corrosive Media ◽  
Corrosion Rates ◽  
Effects Of Ph ◽  
Corrosion Pits ◽  
Corrosive Environments

This paper presents the results of the combined study of experiments and modeling of the pitting corrosion behavior of low carbon steel. The effects of pH are elucidated via experiments on low carbon steel exposed to various corrosive media. The corrosion rates for the steel samples immersed in various corrosive media were determined by polarization experiments via a gamry potentiostat. The microscopic observations of the surfaces reveal clear evidence of corrosion pits that increase in size with increasing exposure duration. The observed pit size distribution and the evolution of pit size are modeled using statistical models. The implications of the results are used for the application of low carbon steels in corrosive environment.

Effect of Soaking Time on Paste Carburizing of Carburized Low Carbon Steel

2017 ◽  
Vol 740 ◽  
pp. 93-99
Author(s):  
Muhammad Hafizuddin Jumadin ◽  
Bulan Abdullah ◽  
Muhammad Hussain Ismail ◽  
Siti Khadijah Alias ◽  
Samsiah Ahmad
Keyword(s):  
Carbon Steel ◽  
Carbon Content ◽  
Low Carbon Steel ◽  
Case Depth ◽  
Carbon Steels ◽  
Low Carbon ◽  
Soaking Time ◽  
Low Carbon Steels ◽  
Carburized Steel ◽  
Carburizing Process

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).

The Corrosion of Carbon Steel and Stainless Steel in Simulated Geothermal Media

1985 ◽  
Vol 38 (8) ◽  
pp. 1133 ◽  
Author(s):  
BG Pound ◽  
MH Abdurrahman ◽  
MP Glucina ◽  
GA Wright ◽  
RM Sharp
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Stainless Steels ◽  
Polarization Resistance ◽  
Iron Sulfide ◽  
Low Carbon Steel ◽  
Passive Films ◽  
Low Carbon ◽  
Corrosion Rates ◽  
Good Agreement

The corrosion rates of low-carbon steel, and 304, 316 and 410/420 stainless steels in simulated geothermal media containing hydrogen sulfide have been measured by means of the polarization resistance technique. Good agreement was found between weight-loss and polarization resistance measurements of the corrosion rate for all the metals tested. Carbon steel formed a non-adherent film of mackinawite (Fe1 + xS). The lack of protection afforded to the steel by the film resulted in an approximately constant corrosion rate. The stainless steels also exhibited corrosion rates that were independent of time. However, the 410 and 420 alloys formed an adherent film consisting mainly of troilite ( FeS ) which provided only limited passivity. In contrast, the 304 and 316 alloys appeared to be essentially protected by a passive film which did not seem to involve an iron sulfide phase. However, all the stainless steels, particularly the 410 and 420 alloys, showed pitting, which indicated that some breakdown of the passive films occurred.

Predicting the Effects of Cold Working on the Machining Characteristics of Low Carbon Steels

1987 ◽  
Vol 109 (3) ◽  
pp. 257-264 ◽  
Author(s):  
E. M. Kopalinsky ◽  
P. L. B. Oxley
Keyword(s):  
Flow Stress ◽  
Carbon Steel ◽  
Cutting Forces ◽  
Cold Working ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Steel Work ◽  
Machining Characteristics

Experiments show that the cold working of low carbon steel work materials can improve their machinability by reducing cutting forces and improving surface finish and tool life. The somewhat paradoxical result of reducing cutting forces by cold working a material so that its hardness is increased is explained in this paper by using a machining theory which takes account of the flow stress properties of the work material and can thus allow for the effects of cold working.

Corrosion Behavior of Al-Si-Cr-Cu Bearing Low Carbon Steel in A Cyclic Dry/Wet Laboratory Test

2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang
Keyword(s):  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Low Carbon ◽  
Rust Layer ◽  
Electrochemical Behaviors ◽  
Corrosion Rates ◽  
The Matrix ◽  
Corrosion Behaviors

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.

A Laboratory Corrosion Inhibition Study of Carbon Steel Using 2-Mercaptobenzothiazole (MBT) under Post-combustion CO2 Capture Conditions

CORROSION ◽  
10.5006/3663 ◽  
2021 ◽  
Author(s):  
Wei Li ◽  
James Landon ◽  
Dali Qian ◽  
Kunlei Liu
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Co2 Capture ◽  
Carbon Steels ◽  
Inhibition Mechanism ◽  
Low Carbon ◽  
Inhibition Study ◽  
Corrosion Rates ◽  
Organic Corrosion Inhibitor ◽  
Carbon Dioxide Co2

Corrosion mitigation is an important aspect of amine-based post-combustion carbon dioxide (CO2) capture operations due to the desire to use less expensive but corrosion-vulnerable materials such as low carbon steels in the construction of a capture system. In this study, the corrosion behavior of A106 (grade B) carbon steel with an in-house proprietary amine-based solvent was investigated in a laboratory environment at 80 °C using an organic corrosion inhibitor, 2 Mercaptobenzothiazole (MBT). The corrosion inhibition mechanism was interpreted by electrochemical methods and surface analyses. The results revealed that the corrosion rates of carbon steel were significantly retarded using MBT. The critical inhibitor concentration was determined to be lie between 10 to 50 ppm under the tested conditions.

Effect of Ti, Al and Mg Addition on the Impact Toughness of Heat Affected Zone in Low Carbon Steel

2009 ◽  
Vol 79-82 ◽  
pp. 143-146
Author(s):  
Jiang Hua Ma ◽  
Dong Ping Zhan ◽  
Zhou Hua Jiang ◽  
Ji Cheng He
Keyword(s):  
Carbon Steel ◽  
Impact Toughness ◽  
Heat Affected Zone ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Carbon Steels ◽  
Low Carbon ◽  
Welding Simulation ◽  
Mg Addition ◽  
The Impact

In order to understand the effects of deoxidizer such as aluminium, titanium and magnesium on the impact toughness of heat affected zone (HAZ), three low carbon steels deoxidized by Ti-Al, Mg and Ti-Mg were obtained. After smelting, forging, rolling and welding simulation, the effects of Al, Ti and Mg addition on the impact toughness of HAZ in low carbon steel were studied. The inclusion characteristics (size, morphology and chemistry) of samples before welding and the fracture pattern of the specimens after the Charpy-type test were respectively analyzed using optical microscope and scanning electron microscopy (SEM). The following results were found. The density of inclusion in Ti-Mg deoxidized steel is bigger than Ti-Al deoxidized steel. The average diameter is decreased for the former than the latter. The addition of Ti-Mg can enhance the impact toughness of the HAZ after welding simulation. The maximal value of the impact toughness is 66.5J/cm2. The complex particles of MgO-TiOx-SiO2-MnS are most benefit to enhance impact toughness. The improvement of HAZ is attributable to the role of particle pinning and the formation of intergranular ferrite.

High Temperature Corrosion of Al Hot-Dipped Low Carbon Steels in N2/H2S-Mixed Gases

2016 ◽  
Vol 369 ◽  
pp. 59-64
Author(s):  
Muhammad Ali Abro ◽  
Dong Bok Lee
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Alloy Layer ◽  
High Temperature Corrosion ◽  
Carbon Steels ◽  
Low Carbon ◽  
Mixed Gas ◽  
Low Carbon Steels ◽  
Mixed Gases

A low carbon steel was hot-dip aluminized, and corroded in the N2/0.4%H2S-mixed gas at 650-850°C for 20-50 h in order to find the effect of aluminizing on the high-temperature corrosion of the low carbon steel in the H2S environment. A thin Al topcoat and a thick Al-Fe alloy layer that consisted primarily of Al5Fe2 and some FeAl and Al3Fe formed on the surface after aluminizing. The corrosion rate increased with an increase in temperature. Hot-dip aluminizing increased the corrosion resistance of the carbon steel through forming a thin protective α-Al2O3 scale on the surface. The α-Al2O3 scale was susceptible to spallation. During corrosion, internal voids formed in the Al-Fe alloy layer, where the Al5Fe2, AlFe, and Al3Fe compounds gradually transformed through interdiffusion.

Feature Extraction of the Acoustic Emission Signals of Low Carbon Steel Pitting Corrosion Based on Independent Component Analysis and Wavelet Transform

2013 ◽  
Vol 373-375 ◽  
pp. 677-680
Author(s):  
Wei Li ◽  
Yu Li Gong ◽  
Yang Yu
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Independent Component Analysis ◽  
Pitting Corrosion ◽  
Wavelet Transformation ◽  
Low Carbon Steel ◽  
Component Analysis ◽  
Independent Component ◽  
Low Carbon ◽  
Ae Signals

Based on the characteristics of the acoustic emission (AE) signals from low carbon steel pitting corrosion, a new extraction method was proposed with wavelet transformation and independent component analysis. The experiment result shows that the new method can overcome the influence induced by the uncertainty of the independent source of low carbon steel pitting corrosion and good extraction result can be achieved.

Deformation and Structure Difference of Steel Droplets during Initial Solidification

2017 ◽  
Vol 36 (4) ◽  
pp. 347-357 ◽  
Author(s):  
Yang Li ◽  
Jing Wang ◽  
Jiaquan Zhang ◽  
Changgui Cheng ◽  
Zhi Zeng
Keyword(s):  
Carbon Steel ◽  
Continuous Casting ◽  
High Carbon Steel ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Solidification Structure ◽  
Low Carbon ◽  
High Carbon ◽  
Peritectic Steel ◽  
Initial Solidification

AbstractThe surface quality of slabs is closely related with the initial solidification at very first seconds of molten steel near meniscus in mold during continuous casting. The solidification, structure, and free deformation for given steels have been investigated in droplet experiments by aid of Laser Scanning Confocal Microscope. It is observed that the appearances of solidified shells for high carbon steels and some hyper-peritectic steels with high carbon content show lamellar, while that for other steels show spherical. Convex is formed along the chilling direction for most steels, besides some occasions that concave is formed for high carbon steel at times. The deformation degree decreases gradually in order of hypo-peritectic steel, ultra-low carbon steel, hyper-peritectic steel, low carbon steel, and high carbon steel, which is consistent with the solidification shrinkage in macroscope during continuous casting. Additionally, the microstructure of solidified shell of hypo-peritectic steel is bainite, while that of hyper-peritectic steel is martensite.

Effects of Stress on Pitting Corrosion Behavior of Low-Carbon Steel

2013 ◽  
Author(s):  
Huaixiang Cao ◽  
Hao Zhang ◽  
Xingqi Qiu
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
High Stress ◽  
Low Carbon Steel ◽  
Pressure Vessels ◽  
Structural Safety ◽  
Low Carbon ◽  
Corrosion Morphology ◽  
Accelerated Corrosion

Low-carbon steel Q235B was widely used in low or middle pressure equipments, which were not only withstanding the corrosive effect of the environment or medium, but also the high stress in service processes. In this paper, acetic acid accelerated corrosion test of low-carbon steel Q235B under the action of various stress levels was conducted, and its pitting corrosion behavior was studied by corrosion morphology, pitting corrosion parameters, scanning electron microscope (SEM) and energy disperse spectroscopy (EDS). The results showed that, the degree of pitting corrosion of low carbon steel Q235B with stress was more serious than that of non-stress. And the corrosion started from grain boundary, which was corroded before grain itself, and then grains fell off or dissolved. Furthermore, it would have the tendency of deep hole corrosion with stress, which was more of a threat to the structural safety of pressure vessels.

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